S4_11-15-04

• Basin: Statewide
• Title: SWSI Phase 1 Report - Section 4 Legal Framework for Water Use
• Date: 11/15/2004
• Author: CWCB
• SWSI - Doc Type: Final Report

Section 4
Legal Framework for Water Use
stream. In the early 1900s, Colorado courts held that
tributary groundwater is subject to the prior appropriation
system.55 The court based its decision, in part, on the
fact that wells that intercept tributary groundwater
actually deplete the stream flow to the detriment of senior
surface appropriators.5s
Non-tributary groundwater is statutorily defined as that
groundwater, outside the boundaries of a designated
basin, "the withdrawal of which will not, within one
hundred years, deplete the flow of a natural stream ... at
an annual rate greater than one-tenth of one percent of
the annual rate of withdrawal."57 The right to use non-
tributary groundwater is purely a function of statute.58
The General Assembly has recognized that non-tributary
groundwater is a finite resource and has specifically
declared that "such water shall be allocated... upon the
basis of ownership of overlying land.59 Rights to use non-
tributary groundwater are limited to "that quantity of
water, exclusive of artificial recharge, underlying the land
owned by the applicant or underlying land owned by
another" who has consented to the applicant's
withdrawal.s~ The annual withdrawal of this type of
groundwater is further limited in accordance with a
100-year aquifer life.s~
Not non-tributary groundwater is groundwater located
within one of the Denver Basin aquifers (the Dawson,
Denver, Arapahoe, and Laramie-Fox Hills aquifers in the
Denver Basin, which extends roughly from Fort Collins to
Colorado Springs and from the foothills eastward), but
outside the boundaries of a designated basin, the
"withdrawal of which will, within one hundred years,
deplete the flow of a natural stream... at an annual rate of
greater than one-tenth of one percent."62 Not non-
tributary groundwater is also allocated on the basis of
land ownership. However, the owner of a not non-
tributary well must have a plan for augmentation in place
before withdrawing such water.s3
Designated groundwater is groundwater that would not
be available to fulfill surface rights or groundwater that
ss Comstock v. Ramsay, 133 P. 1107 (Colo. 1913).
ss Id.
57 § 37-90-103(10.5), C.R.S.
se § 37-90-102(2), C.R.S.
ss Id.
so § 37-90-137(4)(b)(II), C.R.S.
61 § 37-901-137(4).
6z § 37-90-103(10.7), C.R.S. (emphasis added)
s3 § 37-90-137(9)(c)(I), C.R.S.
~~ ~
has been the principal water supply for the area for at
least 15 years and is not adjacent to a naturally flowing
stream.64 Designated groundwater exists within
designated groundwater basins. The Ground Water
Commission establishes designated groundwater basins
through a notice and hearing procedure when evidence
becomes available that groundwater within a specific
geographic area meets the above noted criteria.65 Each
designated groundwater basin is administered according
to a modified prior appropriation system. Locations of
designated groundwater basins are presented in
Section 7.
4.3.9 Reuse
Colorado law generally provides for one use of water by
the original appropriator. The water that is not consumed
by an appropriator's first use is returned to the stream
system, either as surface run-off or through subsurface
infiltration. Junior appropriators, who are entitled to have
stream conditions as they exist at the time of their
appropriation, rely on these return flows to fulfill their
decreed rights.
Thus, water that is brought into a watershed from a
source unconnected with the receiving system termed
"foreign" water may be reused by its owner.ss Foreign
water includes non-tributary groundwater introduced into
a surface stream as well as water imported from an
unconnected stream system ("transmountain water").67
Importers of foreign water enjoy rights of reuse that
native water appropriators do not have. Such water is
deemed "fully consumable" and can be used and reused
to extinction so long as the user maintains dominion and
control over the water. Dominion and control in this
context refers to the intent to recapture or reuse such
water, and is not lost when a municipal provider delivers
water to a customer's tap or when consumers use such
water to irrigate lawns.s$ Dominion over the water is not
lost if the importer intends to reuse such water and has
some method to track or recapture the water.
In addition, agricultural water rights that are changed to
municipal use may also generate fully consumable water
that can be used to extinction. This is because the
64 § 37-90-103(6).
ss § 37-90-106.
ss City of Thornton v. Bijou Irr. Co., 926 P.2d 1,66 (Colo. 1996)
s~ Id.
se Public Service Co. v. Willows Water Dist., 856 P.2d 829, 834
(Colo. 1993).
~~
Sfvtewide Woter Supoly Initiofive
4-10 S:\REPORT\WORD PROCESSING\REPORT\S4 11-7-04.DOC